New aminophenylamidines, their production and their medicinal use

ABSTRACT

4-Amino substituted phenylamidine are anthelmintics. The compounds, of which N-(4-aminophenyl)-N&#39;&#39;,N&#39;&#39;-dimethylacetamidine is a representative embodiment, can be prepared through treatment of a 4-amino aniline with a carboxylic acidamide or thioamide, reduction of an appropriately substituted 4-aminophenylamidine, optionally followed by alkylation of the resultant 4aminophenylamidine, formation of a Schiff base followed by quarternization and hydrolysis, or hydrolysis of a 4acylaminophenylamidine.

Wollweber etv al.

States l atent 1 1 NEW AMINOPHENYLAMIDINES, THEIR PRODUCTION AND THEIR MEDICINAL USE [75] Inventors: Hartmund Wollweber,

Wuppertal-Elberfeld, Germany; Winfried Flucke, Beenleigh, Australia [73] Assignee: Bayer Aktiengesellschaft,

Leverkusen, Germany [22] Filed: June 9, 1971 [21] Appl. N0 151,575

.[30] Foreign Application Priority Data June 13,1970 :Ge'rmuny 2029299 [52] US. Cl... 260/564 R-F, 260/239 B, 260/29375, 260/293.79, 260/326.86 260/465 E, 260/50l.l4, 424/244, 424/267, 424/274, 424/304, 424/316, 424/326 [5 1] Int. Cl. ..L C07c 123/00 [58] Field of Search 260/564 RF, 501 14 [56] References Cited UNITED, STATES PATENTS 3189,6148 6/1965 Gerjovich 260/564 R tion of an 1 51 Dec. 17, 1974 5/l965 Steiger ..260/564R 1/1971 Pallosetal 260/564R Primary Examiner-Leon Zltver Assistant'ExamineFeGerald A. Schwartz ABSTRACT 4-Amino substituted phenylamidine are anthelmintics. The compounds, of which N-(4-aminophenyl)-N,N-

- dimethylacetamidine is a representative embodiment, can be prepared through treatment of a 4-amino aniline with a carboxylic acidamide or thioamide, reducappropriately substituted 4 aminophenylamidine, optionally followed by alkylation of the resultant 4-aminophenylamidine, formation of a Schiff base followed by quarternization and by drolysis, or hydrolysis of a 4-acylaminophenylamidine.

6 Claims, No Drawings 1 v 1 y NEW- AMINOPHENYLAMIDINES, (THEIR I PRODUCTION AND THEIR MEDICINAL use DETAILED DESCRIPTION The present invention relatesto new aminophenylamidines and -cycloamidines and salts thereof,

to processes'for their productiom'and to their use as N-phenylacetamidines, such as N-(p-chlorophenyU- N,N-dimethylacetamidine, are known. These corn- .pounds are also ineffective against helminths.

This invention provides aminophenylamidines and aminophenylcycloamidines of the general formula:

R is a hydrogen atom or an alkyl or alkylene group containing up to three carbon atoms; R is a hydrogen, chlorine or bromine atom or a methyl or cyano group; I I R is a hydrogen, chlorine or bromine atom or an alkyl group with up to three carbon atoms or a methoxy, trifluoromethyl or cyano group; R is methyl or ethyl group; and

- either I R is a methyl or ethyl group or a cycloalkyl group with 3 to 6 carbonatoms; and R is an alkyl or alkoxy group with l to 3 carbon atoms;

'- R and R together are a -(-CI--l group, m being a whole number from 3 to 5;

R is a straight- 'or branc'hed'chain alkyl, alkenyl or alkoxy group; and

R is a hydrogen atom or a straight or branchedchain alkyl, alkenyl, alkynyl or alkoxy group; or R and R together with the amino nitrogen atom and the amidino carbon atom form a five, six or seven.- membered ring; and their salts.

These aminophenylamidines and -cycloamidines and their non-toxic salts are useful-for combating parasites, especially helminths, in human and veterinary medicine.

Alkyl and alkoxy groups R preferably contain 1 to 5, especially 1 or 2, carbon atoms, and the alkenyl group R preferably contains 2 to 5 carbon atoms.

ates,

preferably contain 2 to '5, especially 2 or 3, carbon atoms. The cycloalkyl group R preferably possesses 3 to 7 carbon atoms.

The active substances according to the invention are basic in character. They can be used as free bases or in the form of their salts, i.e., salts of pharmaceutically acceptable acids for example hydrohalides, such as, for example, hydrochlorides, sulphates phosphates, nitrates, acetates, naphthalene disulphonates or pamoi.e., the ,salts with methylene-bis-(2- hydroxynaphthoic acid-3). The preferred salts are the hydrochlorides. 1

Particularly preferred compounds are those of the general formula (l).in which:

new aminophenylamidines and-cycloamidines and their salts.

Process (a)comprises reacting an aniline derivative of the general formula eral formula:

Alkyl groups R preferably contain l to 5, most preferably 1 or 2, carbon atoms, and alkenyl groups R generally contain 2 to 5, preferably 2 or 3, carbon atoms. Alkyl'and'alkoxy groups R and R preferably contain 1 to 6, especially] to 3, carbon atoms, and .alkenyl groups R and R preferably contain 2 to 6, especially 2 to 4, 'carbon atoms.

Alkyl and alkoxy groups R -preferably'contain l-to 4, especially 1 to 3, carbon atoms. The alkenyl and al- ,kynyl groups R preferably'contain 2 .to 4 carbon atoms.

If R and R together with'the amine nitrogen atom form a S-membered to 7-membered ring, R and R together preferably represent the group (Cl-I in. which n-represents 3, 4 or 5'.

and R, R and R to R areas definedabove.

The reaction is optionally carried out in the presence of a condensation agent. The-reaction product can be isolated in the form of one of its salts or in the form of The alkyl grou s R referably contain 1 to 5, es pe- I cially l to 3, carbon atoms, and the alkenyl groups R a free base, and then optionally converted into any other desired salt.

As salts of the carboxylic acid amides (3) there are to be understood both salts with organic acids, (for example, the acetates) and salts with inorganic acids-(for example the hydrohalides or sulphates).

By reactive derivatives of the amides (3) there are, for example, to be understood derivatives which are obtained by reaction of an amide or thioamide of the general formula (3) with an inorganic acid (for example, hydrochloric acid, boron trichloride or sulphuric acid) or with an inorganic or organic acid halide (for example, phosphorus oxychloride,.phosphorus pentachloride, phosgene, thionyl chloride, benzoyl bromide,

p-toluenesulphonyl chloride or a mixture of phosgene/aluminium chloride, or phosgene/hydrogen chloride or phosgene, phosphorus oxychloride) or with a trialkyloxonium fluorborate (1 carbon atoms per alkyl group) or with a dialkyl sulphate (1 5 carbon atoms per alkyl group) or an alkyl halide (l 5 carbon atoms).

As condensation agents that can be employed in process (a), there may for example be mentioned:

Inorganic acids (for example, hydrochloric acid, boron trichloride, sulphuric acid) or inorganic or organic acid halides (for example phosphorus oxychloride, phosphorus pentachloride, 'phosgene, thionyl chloride, benzoyl bromide, p-toluenesulphonyl chloride or a mixture of phosgene/aluminium chloride, or phosgene/hydrogen chloride or phosgene/phosphorus oxychloride) or trialkyloxonium fluorborates (1 to 5 carbon atoms per alkyl group) or dialkyl sulphates (1 to 5 carbon atoms per alkyl group) or alkyl halides (1 to 5 carbon atoms).

When a thioamide is used, i.e. W =sulphur in general formula.(3 a desulphurizing agent, for example, HgO, Ag O or Hg(CN) can be used advantageously in addition to one of the abovementioned condensation agents, or without one of these condensation agents.

The reaction components (2) and (3) are preferably employed in the stoichiometrically required amounts.

The reaction can be carried out in any inert organic solvent; among such solvents, aromatic, optionally halogenated, hydrocarbons, for example, benzene, toluene or dichlorobenzene; optionally chlorinated aliphatic hydrocarbons, for example methylene chloride and chloroform; tetramethylene-sulphone, and lower aliphatic alcohols, for example, methanol and ethanol, should be mentioned.

The reactants are preferably brought together at room temperature (about C) and, if appropriate, are warmed to between and,lC, preferably 80 to 120C, in order to complete the reaction.

The success of the reaction does not depend on the sequence in which the reactants are brought together. The new compounds are isolated in the customary manner.

Process (b) comprises reducing a nitrophenylamidine or -cycloamidine of the general formula:

or a salt thereof, to obtain an aminophenylamidine or -cycloamidine, of the general formula:

i.e. a compound of general formula (I) in which R is hydrogen. This product is then, if a compound of general formula (I) is required in which R is not hydrogen, either i. alkylated with an alkylating agent of the general formula ii. alkylated reductively with an oxo compound of the general formula:

to obtain a Schiff base which is reduced to give the required aminophenylamidine, -cycloamidine or salt.

In the above general formulae (4), (6) and (7), R, R, R to R are as defined above, B is a reactive ester group or a halogen atom; R is a straight-chain or branched alkyl or alkenyl group; R is a hydrogen atom or an alkyl group: and R is an alkyl group.

- thanesulphonyloxy, or alkoxysulphonyloxy (preferably with 1 or 2 carbon atoms in the alkyl or alkoxy group).

The alkyl groups R preferably contain 1 to 5, especially 1 to 4, carbon atoms and the alkyl groups R preferably contain 1 to 5, especially 1 or 2, carbon atoms. The nitrophenylamidines of general formula (4) and their salts can be reduced by any suitable method.

The reduction can advantageously be effected catalytically, for example with Raney nickel as the catalyst,

optionally in the presence of a solvent, such as an alco-' hol, for example methanol or ethanol, a solution of hydrochloric acid in ethanol, or an ether for example tetrahydrofuran, at a temperature of 0 to 100C, preferably of 20 to C, optionally under pressure, for example at l to 100, preferably 60 to 80, atmospheres gauge.

The reduction can also be carried out with zinc/hydrochloric acid and stannous chloride, preferably in an aqueous medium (water).

Furthermore, the reduction can be carried out with sodium sulphide, for example in an alcohol, for example, methanol and ethanol, or in an ether, for example, in tetrahydrofurane, at temperatures of 20 to C, preferably at the boiling point of the solvent.

Further reducing agents which can be used are complex metal hydrides, such as, for example, sodium boranate in alcohol (preferably ethanol)/water, at temperawater, alcohols, for example, methanol or ethanol, ke-

ably employed in approximately molar amounts. Solvents which can be used for this reaction, which is car ried out at to 100C, preferably at about to 60C, are, for example, alcohols, .for'example,.methanol or ethanol ethers for example, tetrahydrofuran, and aromatic hydrocarbons, for example, benzene or toluene.

- The Schiffs base obtained in this manner is hydrogenated, optionally being isolated, by any suitable method. For instance, the base may becatalytically hydrogenated, for example with Raney nickel as the catalyst. The catalytic reduction is preferably carried out at room temperature (about 20C),'and optionally under pressure (1 to 80 atmospheres gauge, preferably 60 at mospheres gauge). As a solvent an alcohol, for example methanol and ethanol, an aromatic hydrocarbon, for

example, benzene and toluene, or an ether, for example, tetrahydrofuran, can be used.

The reduction of the Schiffs base can also be effected by means of a complex metal hydride (approximately stoichiometrically required amounts) for example, sodium borohydride. In this case the reaction is carried out at temperatures of 20 to 80C. Here, alcohols, for example methanol and ethanol, optionally in admixture with water, are preferably used as solvents.

Process (0) comprises reacting an aminophenylamidine or -cycloamidine of the general formula:

is hydrogen, with an aliphatic or aromatic aldehyde to obtain a Schiff base quaternising the Schiff base with an alkylating agent of the general formula:

example benzene and toluene, or an ether for example, tetrahydrofuran.

The Schiff base is quaternised, optionally after being isolated, by means of the alkylating agent (6) by any suitable method, preferably at temperatures between 20 to 100C, especially between 60to 80C. Any inert organic solvent for example benzene, toluene and tetrahydrofurane can be employed. The subsequent hydrolysis is preferably carried out without isolation of the quaternised Schiff base, preferably at temperatures between 20 to 100C, especially between and 90C, and preferably in an aqueous alcohol, especially ethanol. Y

Process (d) comprises hydrolytic splitting of an acylaminophenylamidine or -cycloamidine of the general formula: i

in which R, R and R to R 'are as defined above and R is an acyl or acyloxy group, preferably with l 5 carbon atoms.

The hydrolytic splitting is carried outby any suitable method; many such methods are known in the art.

The hydrolysis is preferably carried out in the presence of a strong acid, such as hydrochloric acid or sul- I i.e. a compound of the general formula (I) in which R g preferably employed in molar amounts. The reaction.

temperatures are preferably between 0 and 80C, preferably between 20 and 40C. Any inert organic solvent may be used, for instance, an alcohol, for example methanol and ethanol, an aromatic hydrocarbon, for

phuric acid. Water, or a mixture of water with an alcohol, is used as a solvent. The hydrolysis is preferably carried out at the' boiling point of the solvent.

The following Examples illustrate the process according to the invention for the production of the new aminophenylamidines and cycloamidines.

All temperatures are given in degrees centigrade (0C).

All starting compounds are known or are obtainable by known processes.

EXAMPLE 1 CH3 'CHa 620 g (3 mols) of N-(4-nitrophenyl)-N',N- dimethylacetamidine in 1250 ml of ethanolic hydrochloric acid (3.3 mols) are hydrogenated with the aid of Raney nickel as the catalyst, at and 80 to atmospheres gauge hydrogen pressure. The mixture is evaporated in vacuo, the residue is taken up in water and rendered alkaline with sodium hydroxide solution, the base which separates out is extracted with ether, the extract is evaporated, and the residue is distilledin vacuo; the product is N'-(4-aminophenyl)- N,N'-dimethylacetamidine, boiling point 02 158 melting point 93 95 (from ethyl acetate); yield 426.5 g, monohydrochloride, melting point 273 274.

The following compounds are obtained by analogous processes: I

R"R'N R' R" R" R" R Boilifigpoinfl 4-H C-HN 2-Cl H CH CH CH l70/0.5 4-H C-HN Z-Br H CH CH CH l78/0.5 4-H HN 2-Cl H CH CH CH l72/0,2 4-H -HN H H CH CH CH l63/0.5 4-H C -HN H H CH CH CH l7l?/0.6 4-(CH HC-HN H H CH CH CH l69/O,6' firgl C-HC=HC-CH H H CH CH CH l78/0.4 4-H C-HN H H CH OCH:, CH, l62/0.4 4-H C-HN 2Cl H C H;, OCH;. CH, l78/0.6 4-CH O-CH -CH -HN l H CH CH CH l80/O.2

EXAMPLE 4v 25 g of N-(4-carbethoxyaminophenyl)-N,',N r I 5 dimethylacetamidine in 100 ml of concentrated hydrov ornv on, chloric acid are heat'ed for 2 hours under reflux. After I cH-oH -HN--N=dJ- -N evaporation,-the'- residue is taken up in water and ren- 2 v (14), dered alkaline with sodium hydroxide solution, and the u il mznj 3 35 g of' the N-(4 isobutylideneaminophen-yl)-N',N'- dimethylacetamidine obtained according to Example 3,

. dissolved in 250 ml of tetrahydrofurane, are hydrogenated with Raney nickel as the catalyst, at 20 50 and 60 atmospheres gauge of hydrogen; After filtering off the catalyst-, and distilling, 17.5 g of N-(4- isobutylaminophenyl -N ,N '-dimethylacetamidine,

' boiling point 1382 l45, are obtained:

EXAMPLE Successive reaction of 2-(4-aminophenyl) imino-N- methylpyrrolidine-with ben zaldehyde and dimethyl'sulsponding way:

aqueous phase jisextracted witha mixture of ether and chloroform. After distillation, 12 g of N-(4- aminophenyl)'-N',N'-dimethylacetamidine, boiling point. l58-l65, melting point 93-95, are obtained. w I I v The fact that the new amino phenylamidines and cycloamidines and their salts show a strong and wideactivity is surprising and unforepounds-constitues a substantial extension of the available range of anthelmintics.

ln-particular, the compounds manufactured according to the invention for example display a surprisingly good and broad action against the following helm'inths (nematodes and cestodes):

l. Nematodes- Bunostomum trigonocephalum (hookworms) from the 1 family of the Ancylostomatidae;

family of the Rhabditidae;

5. Toxocara canis, toxascaris leonina and Ascaris summ larvae (coilworms) from the family of the Ascarididae;

6. Aspiculuris tetraptera (maggot worms) from the family of the Oxyuridae;

7. Heterakis spumosa from the family of the l-leterakidae;

' II. Cestodes,

l. Hymenolepis nana and Hymenolepis mic'rosloma (tapeworms) from the super-family of the Taenioidea. The action of the new compounds was tested in aninum were trated after the end of the pre-patent period of the parasites.

The amount of active compound was administered orally, as the pure active compound or dissolved in strength lactic acid, in gelatine capsules.

The degree of action was determined by counting the worms expelled after treatment and the worms remaining in the test animal after dissection, and calculating the percentage of worms expelled.

The active compounds tested, the dosages used, and the action are summarised in the table which follows.

TABLE l.--H OOKWO RM TESTIDOG S Action Dose, in Active compounds mgJkg. percent Known compounds for comparison:

- CH3 (17) 50 0 C I-IiC ONH-N=CHN\ -HC1 C Us C II: C H a (18) 0 I CH3 ClC:CC1 (19) 300 82 v (20) 51 s- :s

. G3 (21) 4G ll2):-N(( ll:a)2-( llg mo us I -U 0 O1I J 0 NH- C \N (in; CH (0) J9 C II:

CH3 C H3 (24) 10 J4 5 7G -HCl 2. 5 72 1 17 C H:

I OH:

-llCl TABLE l. -Continucd I Action Dose, in I Active compounds man/kg. percent Known compounds for comparison:

-(,lI;| (Ill; (28) 10 J9 II2N N ()N -ll()l *Litcratnrc: Ruwcs, l). A. (15161): Thenctivityol' Bvphonlu n llyclrocynophthoate against llookwormsinthc Dog Vet. Rec. 73 (16),;3!!!) 392.

Literature: Theodorides, V. J. and M. Laden-mun (11168): larbondu ment of Intestinal Nematodes of Dogs and Monkeys. Vet. Med. 63 (10),

EXAMPLE B Hookworm Test/Sheep The amount ofactive compound was administered orallyQas pure active compound, in gelatine capsules.

ole in tho Trout- The active compounds tested, the dosages used and h cti a e $119.!!! iathe l hish follows.

I Table 3: Test on Worm of Large Intenstine/Sheep TABLE 3.TES'I ON'WORM OF LARGE I N'IESTINE/SIIEEP Sheep naturally infected 'with' Chabertia ovina were Pa S- a The amount of active compound was administered orally as pure active compound, in gelatine capsules.-

The degree of dilution is determined by counting the worms expelled after the treatment and the worms remaining in the test anmials, after dissection, and calcu- The degree of action was determined by countin'gthe Dose i; worms expelled after the treatment and the worms re- Active pou d I mg./kg. percent maining in the test animals, after dissection, and calcu- 7 CH3 (9) 10 97 lating the percentage of worms expelled.

HzN N CN The active compounds tested, the dosages used and I I the action are shown in the table which follows. 9 I

' TABLE 2.IHOOKWORM TEST/SHEEP I Action Dose, in I Active compounds mgJkg. I percent CH3 CH3 (9 Base 2.5 95 o 10 100 1r2N-*N N I I Hydrochloride 5 100 I I I v CH3 CH3 v (29 10 07 HQN- -N= cm 1 c1 (26 23 as ]I2N N=LN/ JIIz EXAMPLE 0; EXAMPLE D Test on worm of Large Intestine/Sheep cqilw T 't/D I Dogs naturally infected with ,Toxoc ara'canis or Texast ate aft h e of h -,pre-p tentperiod of the caris leonina were treated orally. The amount of active compound was administered orally, as pure active com-, pound or as a 10% strength solution in lactic acid, in gelatine capsules.

The degree of action is determined by counting the wormsexpelled after the treatment and the worms remaiiiing in the test animals, after dissection, and calculating the percentage of worms expelled.

The active compounds tested, dosages used and action are summarised in the table which follows.

Table 4 Coilworm Test/Dog 'lAB LE 4.COILWO RM TEST/D O G Action Dose, in Active compounds Parasite mg./kg percent CH CH; (24) Toxocara 2.5 100 l Toxascaris 5. 0 96 I'I:N@'N= -N -HCl CH3 CH: (28) Toxocare 10.0 60 l Toxascan's 10.0 80 HzN-N=CN HCl l CH3 In general it has proved advantageous to administer amounts of 0.1 to 50 mg of the new compounds per kg of body weight per day in order to achieve effective rebecause of the variety of animal and its individual behaviour towards the medicament or because of the nature of the formulation of the latter and the point in time, or interval, at which it is administered. Thus, it may in some cases suffice to use less than the abovementioned minimum amount, whilst in other cases the upper limit mentioned must be exceeded. Where major amounts are administered, it may be advisable to divide these into several individual administrations over the course of a day. The same degree range is envisaged for administration in human medicine and in veterinary medicine. The general sense of the other comments made above also applies.

As stated above, the invention also relates to the pharmaceutical us of the new aminophenylamidines and -cycloamidines and their non-toxic salts.

Accordingly, the present invention provides a pharmaceutical composition containing an an active ingredient at least one of the new aminophenylamidines and -cyclo-amidines of the general formula (1) given above, or a non-toxic salt thereof, in admiting with a 1 pharmaceutically acceptable solid or liquid diluent or carrier as hereinafter defined.

In the present specification the expression pharmaceutically acceptable diluent or carrier means a nontoxic substance that when mixed with the active ingredient or ingredients renders it suitable for administration. The expression preferably excludes water and low-molecular weight organic solvents commonly used in chemical synthesis, except in the presence of other pharmaceutically necessary ingredients such as salts in correct quantities to render the composition isotonic, buffers, surfactants, colouring and flavouring agents, and preservatives. Examples of suitable liquid andv solid diluent and carriers are the following:

Buffered aqueous solution; isotonic saline aqueous solutions; non-toxic organic solvents; such as paraffins, (for example petroleum fractions); vegetable oils (for example groundnut and sesame oils); alcohols, (for example ethyl alcohol or glycerol); glycols (for example glucose). Examples of pharmaceutical compositions according to the invention are ointments, pastes, creams, sprays, lotions, aqueous suspensions, emulsions and solutions, elixirs, syrups, granules and powders, either free-flowing or compressed into tablets.

The compounds and pharmaceutically acceptable salts of the present invention may be administered perorally. I

One group of preferred pharmaceutical compositions of the invention are therefore those adapted for oral administration. The diluents and carriers used are preferably therefore those that adapt the active ingredient or ingredients for oral administration. Examples of such diluents and carriers are solid vehicles, excipients and lubricants such as glucose, lactose and sucrose, corn andpotato starch, sodium carboxymethyl cellulose, ethyl cellulose and cellulose acetate, powdered gum tragacanth, gelatin, alginic acid, agar, stearic acid, sodium, calcium and magnesium stearates, sodium lauryl sulphate, sodium citrate, calcium carbonate, and dicalcium phosphate.

The pharmaceutical compositions of the invention may also contain other non-toxic adjuvants and modifiers such as dyes, surfactants, for example, emulsifiers, such as non-ionic and anionic emulsifiers (for example polyoxyethylenefatty acid esters, polyoxyethylene-fatty alcohol ethers, alkylsulphonates and arylsulphonates), and dispersing agents (for example lignin, sulphite waste lyes, methylcellulose, starch and polyvinylpyrrolidone), perfumes, flavouring agents, preservatives and biocides.

The compounds and pharmaceutically acceptable salts of the invention may also be administered parenterally, in particular subcutaneously. A group of preferred pharmaceutical compositions of the invention are therefore those adapted for parenteral injection. The diluents and carriers used are therefore preferably those that adapt the active ingredient for parenteral administration. Examples of such diluents and carriers are solvents and suspending diluents such as water and wa- I ter-miscible organic solvents, in particular sesame oil, groundnut oil, aqueous propylene glycol, N,N- dimethyl formamide. Examples of pharmaceutical compositions of the invention are sterile isotonic saline aqueous solutions of the active ingredient, which may be buffered solutions of the active ingredient, which may be buffered with a pharmaceutically acceptable buffer and are preferably pyrogen-free.

The pharmaceutical compositions of the invention generally contain 0.5 to 90' wt. of .a new aminophenylamidine or -cycloamidine of the invention or a non-toxic saltthereof. r

The present invention also provides medicaments in dosage unit form as thereinafter defined comprising as I an active ingredient at least one aminophenylmidine or -cycloamidine of general formula (1-) given above or a non-toxic salt thereof, either alone or in admixture with a pharmaceutically acceptable solid or liquid diluent or carrier; in this case the diluent or carrier is preferably as defined above but can also be water or another common solvent.

The expression medicament in dosage unit form as v used in the present specification means a medicament in the form of discrete portions each containing a unit dose or a multiple or sub-multiple of a unit dose of the active ingredient(s); for example, one, two, three of four unit doses or a half, a third or a quarter of a unit dose. A unit dose is the amount of the active ingredient(s) to be administered on one occasion and-will usually be a daily dose, or for example a half, a third, or a quarter of a daily dose depending on whether the medicament is to be administered once or, for example, twice, three times, or four times a day.

The disc portions constituting the medicament in .dosageunit form can include a protective envelope. The active ingredient can be undiluted and contained in such an envelope, or can be mixed with a pharmaceutically acceptable solid or liquid diluent or carrier as defined above. Such portions can for example be in monolithic coherent form, such as tablets, lozenges,

pills, suppositories, or dragees; in wrapped or con-' cealed form, the active ingredients being within a protective envelope, such as wrapped powders, cachets,i sachets, capsules, or ampoules; or in the form of a sterile solution suitable for parenteral injection, such as ampoules of. buffered, isotonic, sterile, pyrogen-free aqueous solution; or in any other form known in the art.

- As stated above, it is preferred to administer the new aminophenylamidines and -cycloamidines of general formula (1) or their salts perorally. Preferred medicaments in dosage unit form according to the invention are therefore those adapted for oral administration, such as tablets, pills, dragees, capsules, and cachets, as

well as wrapped powders containing the active ingredient in powdered form with a powdered diluent or carrier for suspension in water before being taken.

' As stated above it is also possible to administer the new aminophenylamidines and -cycloamidines pare nterally. A further group of medicaments in dosage unit form according to the invention are therefore those {adapted for parenteral injection, such asampoules con tainingameasured quantity of a sterile isotonic saline injectable aqueous solution of the new active ingredient, which may be buffered with a pharmaceutically ac- 5 ce'ptable buffer and are preferably free of pyrogens.

The preferred unit dose for administration of the medicaments of the invention is 50 2,250 mg. of active ingredients. This will normally be administered once wherein: R is hydrogen, alkyl of l to 5 carbon atoms; R is alkyl of l to 5 carbon atoms; R is alkyl of l to 4 carbon atoms, alkenyl of 2 to 4 carbon atoms, a'lkynyl of 2 to 4 carbon atoms, 0 cyclo-alkyl of 3 to 6 carbon atoms; and

, nyl of 2 to 5 carbon atoms, or a salt thereof of a pharmaceutically acceptable acid. 2. A compound according to claim 1 wherein R is hydrogen or alkyl of l to 3 carbon atoms, R is methyl or ethyl, R is alkyl of l to 3 carbon atoms and R is methyl or ethyl. 3. A compound according to claim 1 wherein R is alkyl of l to 4 carbon atoms.

sulphate, phosphate, nitrate, acetate, naphthalene disulphonate and pamoate.

5. The compound according to claim 1 which isN-(4- aminophenyl)-N,N'-dimethylacetamidine.

6. The compound according to claim 1 which-is N-(4- methylaminophenyl)-N,N-dimethylacetamidine.

R is hydrogen, alkyl of l to 5 carbon atoms or alke- 4. A salt of a compound of claim 1 wherein said salt is selected from the group consisting of a hydrohalide, 

1. A COMPOUND OF THE FORMULA:
 2. A compound according to claim 1 wherein R1 is hydrogen or alkyl of 1 to 3 carbon atoms, R is methyl or ethyl, R5 is alkyl of 1 to 3 carbon atoms and R6 is methyl or ethyl.
 3. A compound according to claim 1 wherein R5 is alkyl of 1 to 4 carbon atoms.
 4. A salt of a compound of claim 1 wherein said salt is selected from the group consisting of a hydrohalide, sulphate, phosphate, nitrate, acetate, naphthalene disulphonate and pamoate.
 5. The compound according to claim 1 which is N-(4-aminophenyl)-N'',N''-dimethylacetamidine.
 6. The compound according to claim 1 which is N-(4-methylaminophenyl)-N'',N''-dimethylacetamidine. 